Metal salts of alkyl substituted hydroxyaromatic carboxylic acids



Patente d Aug. 12, 1941 METAL SALTS OF ALKYL SUBSTITUTED HYDROXYAROMATIC CARBOXYLIC ACIDS Orland M. Reifl,

Socony-Vacuum Woodbury, N. J., assignor to Oil Company, Incorporated,

New York, N. 2., a corporation of New York No Drawing. Application June 11, 1938, Serial No. 213,183

14 Claims.

This invention relates to the production of certain new chemical compounds or compositions which may be generally designated as the metal salts of wax-substituted hydroxy-aromatic car-= boxylic acids. Although the invention is broadly concerned with chemical compounds or compositions coming within the above designated general classification, it contemplates as a preferred group within such general classification those compounds or compositions which are soluble or miscible with mineral oil. 1

My invention is based upon the discovery that the oil-miscible metal salts of wax-substituted hydroxyaromatic carboxylic mids are of multifunctional activity when blended with viscous mineral oil fractions in that they eflect improvement of several unrelated and related properties of the oil. For example, this preferred oilmiscible group of compounds or compositions coming within the general field of invention contemplated herein are effective, when blended in a minor proportion with mineral oil fractions of the lubricant type, to depress to pour point, improve the viscosity index (V. I.) and inhibit oxidation of the oil. By inhibiting oxidation these oil-miscible salts act to retard the formation of sludge and acidic products of oxidation. The? also have a peptizing action on-such sludge, as

may eventually be formed. Thus, any one of these preferred oil-miscible compounds or compositions may, for example, be used in internal combustion engine lubricants to retard or prevent the sticking of piston rings or prevent the corrosion of bearings, particularly those formed of alloy metal-s normally susceptible to corrosion, etc., and at the same time it will act to depress the pour point and improve the viscosity index of the oil. Through a proper choice of metal substituent (lead, copper, tin or zinc, for example) the load-carrying capacity or lubricity of the oil may also be improved.

It should be understood that the use of these preferred oil-miscible compounds or compositions is not confined to lubricating oils, but

they may be employed in any mineral oil fractions where'one or more of the improved properties recited above is desired. In this regard it is to be understood that the present invention is not concerned with mineral oil compositions to which these preferred oil soluble compounds have been added, such oilcompositions forming the subject matter of myco-pending application Serial No. 206,682 filed May 'i, 1938 (now Patent 2,197,832) to which reference is herein made for further details in the composition of these compounds.

It is to be understood, however, that while my invention contemplates oil-miscible compounds or compositions of the type above referred to as a preferred class or group within the general field of invention, the invention is not limited to such oil-miscible compounds or compositions, since this whole class of new materials is possessed of valuable properties irrespective of oilmiscibility. For examples, these compounds or compositions may be used as such as oil-soluble resins for use in paints and varnishes or as in termediaries in the production of resins, resinlike materials, rubber substitutes, etc. Certain of the compounds or compositions are possessed of valuable pharmaceutical, insecticidal, or similar properties, such for example as those derived from the presence of a particular metal or residual hydroxyl group. Numerous other uses and applications of the compounds or compositions contemplated herein will be readily apparent to those skilled in the art from the following description of their compositions and preferred methods of synthesis.

As has been previously pointed out, the compounds or compositions contemplated by this invention may be broadly designated as metal salts of wax-substituted hydroxyaromatic carboxylic acids. All of the salts contemplated by this invention are characterized-by the present of an aromatic nucleus in which at least one nuclear hydrogen is substituted with an hydroxyl group and another nuclear hydrogen is substituted with a carboxyl group wherein the carboxyl hydrogen is replaced with its equivalent weight of metal.

The compounds or compositions contemplated by this invention are further characterized by vthe fact that at least one hydrogen atom on the aromatic nucleus is substituted with an aliphatic hydrocarbon radical or group characteristic of an aliphatic hydrocarbon of high molecular weigh which I may term a heavy alkyl group.

For obtaining the preferred group of compounds or compositions which are miscible with mineral oil and which possess the multifunctional oilimproving properties, I have found that this heavy alkyl" substituent in the salts under discussion must be derived from a predominantly straight chain aliphatic hydrocarbon of at least twenty carbon atoms such as characterize crystalline petroleum wax. As a matter 'of fact paraflln wax is considered to be a preferred source of the heavy alkyl substituent and it is for that reason that the compounds or compositions described herein are referred to as "wax"-substituted. It is to be understood, however. that the term "wax as used herein, is applied in a broad sense and is intended to include any pure compound or mixture of compounds predominantly aliphatic in nature and containing at least twenty carbon atoms which is susceptible of attachment to an aromatic nucleus to provide a substituent which, in the proper proportions, will impart to the characterizing hydroxyl and carboxylate substituted aryl nucleus the multi-functional oil-improving properties referred to.

In addition to the so called heavy alkyl group or groups, a part or all of the nuclear hydrogen on the hydroxyl and carboxylate substituted aryl nucleus may be replaced with: aliphatic groups containing less than twenty carbon atoms, hy-

droxy. alkoxy, aroxy, alkaryl, aralkyl, aryl, chlorine, nitro. and amino radicals or groups.

a aforesaid, it is important that the metal salts of wax-substituted hydroxyaromatic carboxylic acids preferred for use as oil improving agents have nuclear hydrogen in the aromatic nucleus substituted with aliphatic hydrocarbon material containing at least twenty carbon atoms, such as is derived from petroleum wax, to an extent such that this heavy alkyl substituent comprises a sumcient proportion of the composition as a whole to render the same miscible with the mineral oil fraction in which it is used.

For obtaining a compound or product having the desired oil miscibility, it appears that the aryl hydroxide or hydroxyaromatic constituent should not exceed a certain percentage of the wax or "heavy alkyl substituted composition as a whole.

The critical range in the degree of wax-substitution of the aryl nucleus for obtaining these preferred oil miscible compounds may vary with: (a) the mineral oil fraction in which the improving agent is to be used; (1)) the character of the aromatic nucleus (mono or poly cyclic);

(c) the hydroxyl content of the aryl nucleus (mono or poly hydric); (d) mono or poly substitution of the aryl nucleus; and (a) other substltuents on the aryl nucleus which may be of positive or negative or of neutral mineral oil solubilizing activity. In general it may be said that a polycyclic nucleus appears to require a higher degree of wax-substitution than a monocyclic nucleus and that a polyhydric nucleus requires a higher degree of wax-substitution than a mono hydric nucleus.

In view of the foregoing variables it would be impracticable and probably misleading to attempt to give an expression and figure which would indicate accurately the proper ratio of multifunctional oil addition agents. The ratio hydroxyaromatic constituent to the alkylated hydroxyaromatic constituent which would express a degree of aliphatic substitution that would satisfy all cases taking these variables into account. In general, however, it. may be said that for thesepreferred compounds, the ratio by weight of hydroxyaromatic component in the product tothe corresponding wax-substituted hydroxyaromatic nucleus or component therein should notv be greater than about twenty parts by weight of the former to about 100 parts by weight of the latter, or about twenty percent, when the weight of the hydroxyaromatic nucleus. or component is expressed in terms of its chemically equivalent weight of phenol. It will be observed that this ratio does not take into account any other substituents which may be in of twenty percent, which I may term the "phe- 'nolic ratio, represents what I consider a maximum figure for obtaining these preferred oil miscible products, and in general it will be found that this figure will be lower, the actual ratio, of course, being dependent upon the variable factors enumerated above. I

It will be understood that the products contemplated by this invention may be pure compounds satisfying the general requirements outlined above with any one of the various mono or poly cyclic aromatic hydrocarbons forming the I charactexizing'nucleus and with or without the various other enumerated substituents, the only requisites being that at least one nuclear hydrogen be substituted with a hydroxyl group, at least one nuclear hydrogen be substituted with a metal carboxylate (COOM, where M is metal) group, and at least one nuclear hydrogen be substituted with an aliphatic radical or group containing at least twenty carbon atoms, such as a radical or group predominantly characterizing paraffln wax. However in manufacturing the preferred composition of the present invention by the preferred method ofprocedure, the final product obtained is norm-ally or usually a mixture of different compounds which differ in the character of the heavy alkyl substituents, the number of such substituents on a single nucleus and the number of nuclei which may be attached to a single alkyl group. For a more detailed description of the compounds constituting such a mixture reference is made to my aforementioned Patent 2,197,832.

The preferred procedure for making the metal salts of wax-substituted hydroxyaromatic carboxylic acids contemplated herein involves the steps of first preparing a wax substituted aryl hydroxide, then substituting the hydroxyl hydrogen therein with an alkali or alkaline earth metal to form a wax substituted or "heavy alkyl substituted aryl metal hydroxylate of the corresponding alkali or alkaline earth metal. This may be accomplished by stirring with the finely divided alkali metal or reacting with an alcoholate of the alkali or alkaline earth metal. The alkali or alkaline earth metal hydroxylate thus obtained is then carboxylated to form the alkali or alkaline earth metal salt of the wax-substituted hydroxyaromatic carboxylic acid. The alkali and alkaline earth metal salts thus obtained constitute part of the compounds or compositions contemplated herein. They may also be used as intermediate products for forming the salts of the other metals by a process of double decomposition with an alcohol-soluble inorganicor fatty acid salt.

In thisdouble decomposition reaction, the details of which will be hereinafter described, some of the metal may replace a-nuclear hydrogen in the aromatic ring; but if such compounds form, they are in the minority and, in any" event, are not considered harmful to the product.

The metal substituents in the carboxyl group of the improving agents described herein may sol,

the silver, copper, tin, aluminum, iron, alkali and alkaline earth analytical groups, which include: silver, mercury, lead, and thallium; bismuth, copper, and cadmium; arsenic, antimony. and tin; iron, cobalt, nickel, and manganese: barium, calcium, strontium, and magnesium:

. and sodium, potassium, and lithium, respectively.

Other desirable metals include: titanium, cerium, thorium, vanadium, molybdenum, tungsten, uranium, and platinum. Y

The starting material for the hydroxyaromatic constituent in the alkylation reaction to'obtain wax-substituted hydroxyaromatic products of the type used in the foregoing procedure wherein the nucleus is otherwise unsubstituted, may

be a mono or poly cyclic hydroxy'aromatic compound otherwise unsubstituted; orin certain special cases (to. be hereinafter described) the starting material may be an alkyl-aryl ether or an aralhvl-a'ryl ether. For obtaining an alkylated hydroxyaromatic product containing a substituent .in addition to, or in place of, residual hydrogen, the starting material, for the hydroxyaromatic constituent may bea mono or poly cyclic hydroxvaromatic compound in which part of the nuclear hydrogen is substituted with a member or members of the group consisting -of: alkyl groups containing less than twenty carbon atoms, chlorine, hydroiw, alkoxy, aroxy,

aryl, alkaryl, and arallcyl groups.

Examples of the hydroxyaromatic compounds ,naphthyl methyl ether, chiorphenol, and. the

like. Preference in general is to the monohydroxy phenols otherwise unsubstituted, particular preference being given to phenol and alpha and beta naphthol.

Thealnlation oi the hydroxyaromatic compound with aliphatic hydrocarbon groups containing at least twenty carbon atoms may be accomplished in various ways, such as by a Friedel-Crafts synthesis using a halogenated high molecular weight aliphatic hydrocarbon, such as chlorinated wax, or by reaction with unsaturated high molecular weight aliphatic compounds or higher alcohols in the presence of H2804 as a catalyst.

I have found the Friedel-Crafts type of al lrylation reaction to be particularly adapted to the step of preparing the wax-substituted 1 ydroxyaromatic compounds from which the compounds or compositions described herein are synthesized because it afiords a convenient means of controlling the degree of alkylation or waxsubstitution in obtaining the desired phenolic ratio? for use in the preferred mineral oil com-. positions contemplated by this invention.

In this reaction an appropriate halogenated high molecular weight aliphatic compound or material such as mono or poly chlorine-substituted aliphatic compound or material containing at least twenty carbon atoms, for example,- chlorinated petroleum wax, is reacted with the desired hydroxyaromatic compound in the presence oil a catalytic amount of aluminum chloride. Pure or substantially pure mono or poly drocarbon of carbon chain length of twenty or.

chlorine-substituted aliphatic compounds satisfying the above requisites may be used. However, as will be readily understood by those skilled in the art, since it is usually very dimcult to prepare or obtain high molecular weight aliphatic hydrocarbons in a pure or substantially pure state and since it is equally difilcult to prepare the chlorine (or other halogen) substitution productsof such hydrocarbons in a pure or substantially pure state, I prefer to employ a mixture-of such hydrocarbons, such as a suitable petroleum fraction (special preference being given to petroleum wax of melting point not substantially less than about F), as the starting material, converting it into a mixture of different chlorine (or other halide) substitution products by any suitable method for use in the alkylation step. It will be understood, of course,

that when such a mixture of high molecular I weightaliphatic hydrocarboii is employed in the allgvlation reaction, the resulting alkylated product and the metal salt ultimately derived therefrom will also be a mixture of compounds, the individual compounds thereof diflering from each other with respect to the nature of the alkyl substituent. Thus, the ultimate product obtained from a wax-substituted phenol, which may be termed. the salt of a wax-substituted hydroxy-aromatic carboxyllc acid, where alkyla= tion was efiected with a halogenated petroleum wax, such as parafllnwax, will be a mixture of alkylated aromatic compounds difl'ering in composition as the aliphatic constituents of the wax difler in composition. In.other words, the

allavl substituents on the various alkylated hydroxyaromatic carboxylates of a mixture obtained from paramn' wax are predominantly radicals of at least twenty carbon atoms corresponding substantially to the different aliphatic hydrocarbons contained in parailin wax.

In the event it is desired to obtain a'waxsubstituted hydroxyaromatic metal carboiwlate more carbon atoms (such as eicosylene, carotene, melene, etc.) or a higher alcohol of chain length of twenty or more carbon atoms (such as ceryl alcohol, myricyl alcohol, etc.) using H2304 as a catalyst.- By this procedure, the hydroxyaromatic ether can be alkylated without substantial rearrangement taking place. As an alternative procedure, polyhydric phenols can be alkylated by reaction with higher alcohols or high molecular weight unsaturates or by Friedel-Crafts reaction followed by substitution of one hydroxyl hydrogen with a low molecular weight alkyl group. In carrying out this latter procedure, the alkylated polyhydric phenol is treated with an alkali alcoholate to introduce alkali metal into one OH group followed by treating with the desired alkyl halide, whereby the substitution to provide the alkoxy group is effected. I

When it is desired to obtain a nitro or amino group as a substituent in the aryl nucleus, the hydroiwaromatic compounds are alkylated or wax-substituted when free of nitro or amino groups, and such alkylation is followed by nitration of the alkylated compound to introduce the The following description illustrates a preferred procedure which may be followed in synthesizing the metal salts of wax-substituted hydroxyaromatic carboxylic acids contemplated by this invention. The compounds or products obtained from the synthesis described below fall into that class or group of compositions hereinabove referred to as preferred because of their PREPARATION or METAL SALTS or WAX-SUBSTITUTED PHENOL GARBOXYLIC Acm (1) Alkylation of phenol A paraffin wax melting at approximately 120 F. and predominantly comprised of compounds having at least twenty carbon atoms in their molecules is melted and heated to about 200 F., after which chlorine is bubbled therethrough until the wax has absorbed from sixteen per cent to twenty per cent of chlorine, such a product having an average composition between a monochlor wax and a dichlor wax or corresponding roughly to a dichlor wax. Preferably the chlorination is continued until about one-fifth the weight of the chlorwax formed is chlorine. A

quantity of chlorwax thus obtained, containing three atomic proportions of chlorine, is heated to a temperature varying from just above its 1 melting point to not over 150 F., and one mole of phenol (CsHsOH) is admixed therewith. The

' mixture is heated to about 150 F., and a quantity of anhydrous aluminum chloride corresponding to about three per cent of the weight of chlorwax in the mixture is slowly added to the mixture with active stirring. The rate of addition of the aluminum-chloride should be sufiiciently slow to avoid violent foaming, and during such addition the temperature should be held at about 150 F. After the aluminum chloride has been added, the temperature of the mixture may be increased slowly over a period of from fifteen to twenty-five minutes to a temperature of about 250 F. and then should be more slowly increased to about 350'F. To control the evolution of 1501 gas the temperature of the mixture is preferably raised from 250 3!. to 350 F. at a rate of approximately one degree per minute, the whole heating operationfvoccupying approximately two hours from the time of adding the aluminum chloride. If the emission of HCl gas has not ceased when the final temperature is reached, the mixture may be held at 350 F. for a short time to allow completion of the reaction. But to avoid possible cracking of the wax,'the' mixture should not be heated appreciably above 350 F., nor should it be held at that temperature for any extended length of time.

It is important to the formation of a preferred oil-miscible product that all unreacted or nonalkylated hydroxyaromatic material (phenol) remaining after the alkylation-reaction be removed. Such removal can be effected generally by water-washing, but it is preferably to treat the water-washed product with super-heated unreacted material and accomplishing the drying of the product in the same operation.

A wax-substituted phenol prepared according to'the above procedure, in which a quantity of chlorwax containing three atomic proportions of chlorine (twenty per cent chlorine in -the chlorwax) is reacted with one mole of phenol, may, for brevity herein, be designated as waxphenol (3-20) Parenthetical expressions of this type (A-B) will be used hereinafter in connection with the alkylated hydroxyaromatic compounds to designate (A) the number of atomic proportions of chlorine in chloraliphatic' material (chlorwax) reacted with one mole of hydroxyaromatic compound in the Friedel-Crafts reaction; and (B) the chlorine content of the chloraliphatic material (chlorwax). In the above example A=3 and 3:20. This same designation will also apply to the salts of the carboxylic acids derived from these alkylated hydroxyaromatic compounds.

Wax-phenol (Ii-20) as obtained by the above procedure had a phenol content or a "phenolic ratio" of about sixteen per cent. My research indicates that this phenolic ratio of sixteen per cent may be considered as representing about the maximum for satisfactory miscibility in viscous oils of the metal salts of alkylated hydroxyaromatic carboxylic acid" in which the allgvl substituent is derived from petroleum wax and the hydroxyaromatic constituent is derived from phenol (CsHsOH). Effective oil-improving agents can, however, be obtained from waxphenol (3-16) in which the phenol content or phenolic ratio is in the neighborhood of thirteen per cent.

(2) Formation of mar-substituted alkali or alkaline earth metal phenate As an example of this step in the preparation of my oil-improving agents, wax-substituted sodium phenate can be prepared by the reaction of wax-phenol with metallic sodium in the presence of a non-oxidizing gas. The reaction mixture is heated at 500 F. during a two-hour period with rapid stirring to produce finely divided sodium and thereby accelerate the reaction. The proportions of reactants which were used in preparing a wax-substituted alkali metal phenate according to the above procedure were:

Grams Wax-phenol (13.2% combined phenol content) Sodium or equivalent amount of potassium l6 Wax-substituted phenates of the alkali and alkali earth metals may also be prepared by reacting a wax-phenol with the desired alcoholate or steam, thereby insuring complete removal of the alkyl metal oxide of an alkali or alkaline earth metal. For this purpose anhydrous methyl and ethyl alcohols are usually most suitable for use in preparing the alkyl metal oxides. As an example, 500 grams of wax-phenol (3-16) of 13 .2 per cent combined phenol content was reacted with sixteen grams of sodium in the form of the ethyl sodium oxide by heating the mixture to about 300 F. during a one-hour period and allowing the alcohol released in the reaction to distill off, thereby obtaining the wax-substituted sodium phenate as the final product.

A product of the foregoing step, such as the wax-substituted sodium phenate, is heated to a ONa I +00, 0

By rearrangement the carboxy group is transferred to the ring, giving the sodium salt of th phenol .carboxylic acid:

OCOONa on Other carboxylating' reactions may be used in this step of the process, such as the reaction of the alkali metal wax-phenate with carbonyl chloride or carbon tetrachloride; but since the salt formed in the presence of CO: is obtained in high yield and in a pure state,'this is the preferred carboxylation procedure. Although pressures in the neighborhood of 500 pounds per square inch are mentioned above in the description ofthe preferred carboxylation procedure, it may under certain circumstances be more desirable touse lower pressures or even to effect the carboxylation atatmospheric pressure.

A Because of the high viscosity'of the mixture it is advantageous to dilute the wax-substituted phenol initially with one or two parts of mineral oil. When a diluent has been used, the mixture can be stirred more readily, making it suitable to introduce the CO: at a lower temperature. By introducing the C0: under pressure at room temperature and gradually raising the mixture to 350 F. the temperature can be more readily controlled. When CO2 is introduced under pressure at 350 F., rapid changes in viscosity occur, making it more, diflicult to control the temperature of the reaction mixture. v

The product of this step, where the starting material was wax-substituted sodium phenate, is the sodium salt of wax-substituted phenol carboxylic acid.

(4) Formation of the salts of other metals with an alkali or alkaline earth metal salt,

' A wax-naphthol (3-14) was obtained from thethe starting material, the corresponding salts of the other metals can be prepared by double decomposition of the first-mentioned salt with an alcohol-soluble inorganic or fatty acid salt of the desired metal. The use of alcohol as a solvent for the salt is desirable to insure proper solution and reaction, the reaction being conveniently carried out by heating the mixture at 175 F. during a two-hour period.

The reaction product of this doubledecomposition can be purified by diluting the mixture with alight mineral oil and settling out the insoluble reaction salts, followed by removal of the diluent by distillation to obtain the finished product. Another procedure of purification is to wabe formed in the water-washing operation by the use of an alcohol such as amyl' alcohol.

The reaction mixture employed in this double decomposition reaction may, for example, consist of one mole of the sodium salt of wax-substituted phenol carboxylic acid and one mole equivalent of the inorganic or fatty acid salt of the desired metal in alcohol solution. Onepart by volume of Stoddard solvent may be employed as a diluent for the mixture.

In. the formation of polyvalent metal salts of wax phenolic acids by carrying out thedouble decomposition in non-aqueous medium, alcoholsoluble inorganic or fatty acid salts are required.

The reaction may also be carried out in aqueous medium,..in which case a water-soluble inorganic salt of a polyvalent metal is used.

METAL SAL'rs or Wax-Sussrrrumn Narnrnor. CAB- noxmo Acm In addition to'the saltsjust discussed above I have, by following'the same procedure, prepared metal salts of wax-substituted naphtholic acid.

alkylation reaction. This product and the corresponding salts obtained therefrom had a com--- bined naphthol content of sixteen per cent and an equivalent phenol content or "phenolic ratio" of 9.7 per cent. V I

The "salt-s obtained by the exemplary procedures described above are, as the result of their relatively low "phenolic ratio or combined phenol content, all oil-miscible or oil-soluble products. Although products of this type are designated herein as preferred, because of their multifunctional oil-improving properties, it is the petroleum industry as intermediaries in the production of resins. Furthermore, as the phenol content is increased beyond the limits necessary for mineral oil-miscibility. the products lose their waiw characteristics and become rubber-like in character and show definite promise as rubber substitutes without any substantial amount of additional treatment. v

, Compounds or compositions of boththe oil- I miscible and non-miscible types have been prepared, and of the oil-miscible products synthesized all have been tested as additive agents for viscous mineral oils andhave been found to be of multifunctional activity, improving the pour point and viscosity index and inhibiting oxidation of viscous mineral. oil fractions. The following iist is illustrative of the various oil-miscible metal salts of wax-substituted hydroxy-aromatic acids, which I have prepared and tested to demonstrate their value as additive agents for viscous mineral oils.

Table Cupric salt of wax phenol carbowlic acid (3-16) Aluminum'salt of wax phenol carboxylic acid Zinc salt of wax phenol carboxylic acid (3-16) Chromic salt of wax phenol carboxylic acid Ferric salt of wax phenol carboxylic acid (3-16) Cobaltous salt of wax phenol carboxylic acid Nickelous salt of wax phenol carboxylic acid Manganous salt of wax phenol carboxylic acid Calcium salt of wax phenol carboxylic acid Magnesium salt of wax phenol carboxylic acid Potassium salt of wax phenol carboxylic acid Sodium salt of wax phenol carboxylic acid (2-16) Sodium salt of wax phenol carboxylic acid (3-20) Stannous salt of wax phenol .carboxylic acid Zinc salt of wax phenol carboxylic acid (3-20) Aluminum salt of wax phenol carboxylic acid Sodium salt of wax phenol carboxylic acid Sodium salt of wax phenol carboxylic acid Sodium salt of wax-beta naphtholic acid (3-18) Sodium salt oi. wax-alpha naphtholic acid (3-18) I claim:

1. A metal salt of an alkyl-substituted hydroxyaromatic carboxylic acid 'invwhich the alkyl substituent contains atrleast twenty carbon atoms and is attached to the aryl nucleus.

2. A metal salt 01' an alkyl-substituted hydroxyaromatic carboxylic acid in which the alhydroxide with chlorinated paraflln wax in proportions such that the aryl hydroxide constituent in the resulting wax-substituted aryl hydroxide product comprises a substantially smaller proportion of said product than the wax substituent; substituting th hydroxyl hydrogen of said wax-substituted aryl'hydroxide product with an alkali metal; carboxylating the metal-substituted product to form an alkali metal carboxylate: and

kyl substituent contains atleast twenty carbon 7 atoms and is attached to the aryl nucleus, said composition being miscible with mineral oil and possessing theproperty of improving the pour point and viscosity index and inhibiting oxidation of a viscous mineral oil fraction when admixed therewith.

3. A metal salt of an alkyl-substituted phenol carboxylic acid in which the alkyl substituent contains at least twenty carbon atoms and is attached to the aryl nucleus.

4. A metal salt of an alkyl-substituted phenol carboxylic acid in which the alkyl substituent contains at least twenty carbon atoms and is attached to the aryl nucleus, said composition being miscible with mineral oil and possessing the property of improving the pour point and viscosity index and inhibiting oxidation of a viscous mineral oil fraction when admixed therewith.-

5. A metal salt of an alkyl-substituted naphthol carboxylic acid in which the alkyl substituent contains at least twenty carbon atoms and is attached to the aryl nucleus.

6. A metal salt of an alkyl-substituted naphthol carboxylic acid in which the alkyl substituent contains at least twenty carbon atoms and is attached to the aryl nucleus, said composition being miscible with mineral oil and possessing the property of improving the pour point and viscosity index and inhibiting oxidation of a viscous mineral oil fraction when admixed therewith. l

7. A product obtained by condensing an arylhydroxide with chlorinated parafiln wax in proportions such that the aryl hydroxide constituent in the resulting wax-substituted aryl hydroxide product comprises a substantially smaller proportion 01 said product than the wax substituent: substituting the hydroxyl hydrogen of said wax-substituted aryl hydroxide product with an alkali metal; and carboxylating the metal-substituted product.

8. A product obtained by condensing an aryl replacing said alkali metal of said carboxylate with another metal by doubleidecomposition with a salt of said other metal.

9. A product obtained by condensing'phenol phenate: and then carboxylating said wax-substituted metal phenate.

10. A product obtained by condensing phenol with chlorinated parafln wax in proportions such that the wax-phenol formed has a combined phenol content not toexceed twenty per cent; replacing the hydroxylhydrogen oil-the phenol with an alkali metal to form a wax-substituted alkali metal phenate; then carboxylating said wax-substituted alkali metal phenate; and finally replacing the alkali metal with another metal by a double decomposition between said waxalkali metal phenate and a salt oi! said other metal.

11. The method of preparing a metal salt 0! a paraflin wax-substituted hydroxyaromatlc acid which comprises: condensinga chlorinated paraflin wax with an aryl hydroxide in the presence of aluminum chloride to form a wax-substituted aryl hydroxide; heating the wax-substituted aryl hydroxide and reacting same with an alcoholate of a metal selected from the group consisting or alkali and alkaline earth metals, to form the wax-substituted aryl hydroxylate of said metal; and finally carboxylating the product oi! the preceding step by passing carbon dioxide gas into the reaction product in sufllcient quantity 13. As a composition oi. matter, an intimate mixture of the metal salts of alkyl substituted hydroxyaromatic carboxyllc acids, the said acids differing from each other with. respect to the nature of the alkyl substituents and the salts having the carboxyl hydrogen substituted with the same metal, the alkyl substituents comprising essentially aliphatic hydrocarbon groups having a composition corresponding substantially to the different aliphatic hydrocarbons contained in paraflln wax, the said alkyl substituent comprising a suflicient proportion 01. said composition to render the same miscible with mineral oil, said composition possessing the property of improving the pour point, improving the viscosity index and inhibiting oxidation oi. a viscous minoral oil Iractionwhen admixed therewith.

14. As a composition of matter, an intimate mixture ofthe 'meta1 saits'ot alkyi substituted hydroxyaromatic carboxyiic acids, the said acids differing from each other with respect to the fnatu're of thenlkyl substituents and the salts having the carboxyl hydrogen substituted with the same metal, the alkyl substituents comprisin paraiiin wax, the metal substituent in the car-' boxy! group being selected from the group oon sistingoi copper. tin, zine, chromium, mange- .nes'e, iron, and cobalt.

om'nnn m. 

